Question #15626

Happy Numbers.. Java Program
A happy number is built by adding the squares of its digits, doing this permanently, the numbers will end in 1 or 4.
if a positive integer ends with 1, then it is a happy number.
the first few happy numbers are: 1,7,10,13,19,23,28 ...
solution : 13 = 1^2 +3 ^2 = 1+9 = 10
10 = 1^2 + 0+2 = 1+0 = 1
how many positive happy numbers are there in less than 300,000?

Expert's answer

public class main {

/**

* @param args

*/

public static void

main(String[] args)

{

int count=0;

for(int

i=1;i<300000;i++)

{

int

var=i;

var=getSqSumm(var);

while(var>9)

{

var=getSqSumm(var);

}

if(var==4||var==1)

{

count++;

}

}

System.out.println(count);

}

public

static int getSqSumm(int numb)

{

int var=numb;

int

res=0;

while(var>0)

{

res+=Math.pow(var%10,2);

var/=10;

}

return

res;

}

}

/**

* @param args

*/

public static void

main(String[] args)

{

int count=0;

for(int

i=1;i<300000;i++)

{

int

var=i;

var=getSqSumm(var);

while(var>9)

{

var=getSqSumm(var);

}

if(var==4||var==1)

{

count++;

}

}

System.out.println(count);

}

public

static int getSqSumm(int numb)

{

int var=numb;

int

res=0;

while(var>0)

{

res+=Math.pow(var%10,2);

var/=10;

}

return

res;

}

}

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